High Idle After Cleaning Iacv

[Lsquared88]

Hello...I have a 98 ES 300 with 105,000 miles and recently my car has been having a problem. When I start my car, the engine will start up but the idle will get lower and lower until the engine dies. If I start the car and give it some gas it will be ok. I searched the forums and found out that I need to clean the IACV, which I did (thanks to detailed write ups :D) but now the problem is when I start my car, the idle is real high. It idles at 2500 rpm and slowly rises to about 3000 rpm in about a minute or so. After about a minute, the idle will reach 2000 rpm and jump to 2500 rpm back and forth.

I have tried resetting the 15 EFI fuse, checking vacuum lines and hoses, unplugged the battery, and still no luck. I'm not sure what else to do. I don't think it's safe to drive the either. Any suggestions? TIA

[SKperformance]

You have a vacuum leak , check your hoses.

[Lsquared88]

I checked my hoses and they look to be ok

I drove the car around the block and definitely heard some kind of hissing sound from the engine...rpm still won't go below 1700

come to think of it, when i was taking apart the black coil and IACV, there was some kind of sticky gasket between them and half stayed on the IACV and other half stayed on the black coil...can i replace that gasket? if so, where can i pick one up?

it's weird no CEL either

Your thoughts...thanks!!!

[R.Holmes]

I checked my hoses and they look to be ok

I drove the car around the block and definitely heard some kind of hissing sound from the engine...rpm still won't go below 1700

come to think of it, when i was taking apart the black coil and IACV, there was some kind of sticky gasket between them and half stayed on the IACV and other half stayed on the black coil...can i replace that gasket? if so, where can i pick one up?

it's weird no CEL either

Your thoughts...thanks!!!

There is a gasket between the coil and the body of the IACV. If you lost that gasket or broke it when removing the coil to clean it, then that is more than likely where the vacum leak. Lexus or Toyota dealer will have it. If that does not solve the problem. take another look at the hoses that you might have disconnected. It only takes a minor leak and you can very easily miss the leak. Try the gasket first.

[SKperformance]

you know where to look and fix then

[Lsquared88]

Well I bought some ultra black RTV and used it on the black coil and the IACV...rpm didn't jump anymore but high rpm was still there

So I figure wat the heck, I'll buy a new IACV and install it...now everything is working fine :D

I appreciate everyones help with my situation...thank you!!!

[SKperformance]

they take alot of cleaning to get the iacv to work again after it gets locked up.